Alcohol leaves the body at about one standard drink per hour, and a breath or blood test detects it for up to 24 hours after the last drink.
Alcohol produces short-term and long-term effects on the body. Excessive alcohol consumption damages health and produces alcohol use disorder.
Alcohol reaches people differently. One person feels the effects after a single drink where another feels little.
For a person with alcohol use disorder, knowing how long alcohol stays in the system, and which factors change that, informs both the decision to drink and the decision to seek treatment.
How Long Does Alcohol Stay in Your System?
The liver processes one standard drink per hour. A standard drink is 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of liquor.
Blood alcohol concentration (BAC) measures the amount of alcohol in the body as a percentage, and most states set the legal limit for driving at a BAC of 0.08%.
That one-drink-per-hour rate is an average rather than a fixed figure. Body size, liver function and recent food intake move it in either direction, which is why two people who drink the same amount of alcohol clear it on different timelines.
How Does the Body Process Alcohol?
Alcohol absorbs into the bloodstream through the stomach and small intestine, travels to the liver, and leaves the body through sweat, urine and breath.
The stomach and the liver do different jobs in that sequence. The stomach controls how fast alcohol enters the blood, and the liver controls how fast it leaves. The two sections below take each in turn.
What Does the Stomach Do to Alcohol?
The stomach absorbs 20% of the alcohol a person drinks, and an empty stomach speeds that absorption, which produces faster intoxication and a higher BAC.
Alcohol absorbs faster on an empty stomach, which is why drinking without eating produces quicker intoxication and higher BAC levels. Food slows the same process and holds down rapid rises in BAC.
The remaining 80% of the alcohol passes into the small intestine. The stomach therefore sets the speed of intoxication without being the primary site of alcohol metabolism.
What Does the Liver Do to Alcohol?
The liver is the primary site of alcohol metabolism. The liver breaks alcohol into acetaldehyde, a toxic byproduct, then into acetate, which leaves the body through urine, sweat and breath.
Acetaldehyde is the stage of alcohol metabolism that does the damage. Acetaldehyde is toxic to the liver and to other organs, and it is the reason sustained heavy drinking scars liver tissue rather than passing through.
Liver disease impairs liver function and slows that whole sequence, which produces higher BAC levels and raises the risk of harm from any given amount of alcohol.
How Long Does It Take Your Body to Metabolize Alcohol?
The body metabolizes one standard drink per hour, and body size, sex, age, food intake and drinks per hour each change that rate.
The amount and type of alcohol consumed, metabolic rate and other health conditions all move the figure. The five factors below account for most of the difference between two people who drink the same amount of alcohol.
There are 5 factors that change how long the body takes to metabolize alcohol:
- Body size. Larger people carry a higher water content, which dilutes alcohol and reduces its effects. People with higher body fat percentages metabolize alcohol more slowly and stay intoxicated longer.
- Sex. Women carry lower body water content and less of the enzyme alcohol dehydrogenase (ADH) in the stomach, which slows alcohol metabolism and extends the time alcohol stays in the body.
- Age. The body metabolizes alcohol less efficiently with age, which extends intoxication and raises the risk of harm.
- Food intake. Eating before or during drinking slows the rate at which alcohol absorbs into the bloodstream, which reduces the effects of alcohol and speeds the metabolic process.
- Drinks per hour. Drinking too much too quickly overwhelms the liver’s capacity to process alcohol, which extends intoxication and raises the risk of harm.
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What Other Factors Change How Alcohol Is Metabolized?
Binge drinking, the type of alcohol and the absorption rate each change how the body metabolizes alcohol, and all three raise BAC.
Binge drinking, meaning large amounts of alcohol consumed in a short period, slows the rate of metabolism and raises BAC levels. Mental health conditions and other health conditions change how the body metabolizes alcohol and raise the risk of harm.
There are 3 further factors that change how alcohol is metabolized:
- Binge drinking. Consuming a large amount of alcohol in a short period raises BAC levels and slows the metabolic rate.
- Type of alcohol. Wine carries a higher alcohol content than beer or mixed drinks, which raises BAC levels and slows the metabolic rate.
- Absorption rate. Carbonated drinks, and alcoholic drinks consumed through a straw, absorb faster and raise BAC levels. Medications and other substances interact with alcohol and change its absorption rate.
How Long Does It Take to Feel the Effects of Alcohol?
Alcohol reaches the body within 10 to 15 minutes of a drink, and the effects peak within 45 to 90 minutes.
Both windows shift with the same factors that govern alcohol metabolism, and individual responses vary widely even between two people who match on every one of them.
Drink responsibly and stay aware of your limits, if you choose to drink alcohol.
Which Tests Detect Alcohol in the Body?
Breath, blood, urine and saliva tests all detect alcohol. Blood tests are the most accurate, and urine and saliva tests detect alcohol for up to 24 hours after the last drink.
Each test measures the level of intoxication and the amount of alcohol in the system, and they trade accuracy against how invasive and how practical they are.
Blood tests carry the highest accuracy and require a trained professional to administer. Urine tests are less invasive at lower accuracy. Saliva tests match urine tests on the alcohol detection window at lower accuracy again, and clinicians use them least. The three sections below set out how each one works.
How Do Breath Tests Detect Alcohol?
A breath test measures the alcohol in a person’s breath, which corresponds directly to the alcohol in their blood.
Breath tests, also called breathalyzers, are the common way to test for alcohol in the body, and law enforcement officers use them to test for driving under the influence (DUI).
Breath test accuracy varies with the type of alcohol consumed, the person’s breathing pattern and other substances present in the breath, which is why a blood test confirms a contested breath result.
How Do Blood Tests Detect Alcohol?
A blood test measures the concentration of alcohol in the blood directly, which makes it the most accurate test available.
Clinicians use blood tests to test for alcohol-related conditions such as liver damage and alcohol poisoning. Forensic investigators use them to establish the blood alcohol concentration of people involved in accidents or crimes.
A blood test is invasive and requires a trained professional, which rules it out at the roadside and in most workplace settings.
How Do Urine Tests Detect Alcohol?
A urine test measures alcohol metabolites rather than alcohol in the blood, which makes it less accurate than a blood test.
Workplaces and probation services use urine tests to monitor people for alcohol use, because a urine test is non-invasive and needs no clinician to administer.
Urine alcohol results vary with hydration levels, kidney function and the time since the last drink, so a urine result establishes that a person drank rather than how much.
How Is Alcohol Use Disorder Treated?
Treatment for alcohol use disorder covers medication, therapy, support groups, and inpatient or outpatient rehabilitation.
Treatment is what carries a person with alcohol use disorder (AUD) into recovery. Treatment programs supply the tools and the resources a person needs to end an addiction and hold sobriety.
There are 4 treatment options for alcohol use disorder:
- Residential and inpatient rehab. A residential treatment program suits severe alcohol addiction, because it supplies a structured and supervised environment for detox and for building the coping skills that prevent relapse.
- Outpatient rehab treatment. An outpatient program delivers therapy and counseling while a person lives at home, which allows them to continue working and to meet other responsibilities during treatment.
- Medication-assisted treatment (MAT). MAT uses naltrexone, disulfiram and acamprosate to reduce cravings and withdrawal symptoms, which makes sobriety easier to hold.
- Support groups. Alcoholics Anonymous (AA) and SMART Recovery supply a community where people with alcohol use disorder share their experience and connect with others in the same position.
Get Help Today at Riverside Recovery of Tampa
Riverside Recovery of Tampa treats alcohol use disorder in Tampa, Florida, and builds each treatment plan around the individual.
The clinical team at Riverside Recovery of Tampa supplies the support and guidance that carries a person through alcohol use disorder into lasting recovery.
Contact our team today to learn more about our alcohol use disorder programs and how treatment starts.
National Institute on Drug Abuse. (2018). Principles of Drug Addiction Treatment: A Research-Based Guide.
National Institute on Alcohol Abuse and Alcoholism. (2014). Alcohol Use Disorder: A Comparison Between DSM–IV and DSM–5.
Substance Abuse and Mental Health Services Administration. (2016). TIP 57: Trauma-Informed Care in Behavioral Health Services.
National Institute on Alcohol Abuse and Alcoholism. (2018). Treatment for Alcohol Problems: Finding and Getting Help.
Alcohol Breath Tests: What They Are, How They Work, and Their Limitations.” National Institute on Alcohol Abuse and Alcoholism. https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/alcohol-breath-tests-what-they-are-how-they-work-and-their.
- The Accuracy of Breath Alcohol Analysis in Clinical and Forensic Settings.” Journal of Forensic Sciences, vol. 63, no. 4, 2018, pp. 1099-1104. doi: 10.1111/1556-4029.13787
- Measurement of Ethanol in Urine.” Journal of Analytical Toxicology, vol. 36, no. 5, 2012, pp. 305-311. doi: 10.1093/jat/bks036
- Ethanol Blood Tests: How They Work and What the Results Mean.” Mayo Clinic, https://www.mayoclinic.org/tests-procedures/ethanol-test/about/pac-20393857